"I'm happy for Stephen and looking forward to having him join our program," Vanderbilt coach Derek Mason said in a statement. "Stephen brings both ability and experience to our team, and he fits the offensive system we will run under (offensive coordinator) Karl Dorrell. I'm looking forward to seeing great competition at the quarterback position this August."

Rivers will get the opportunity to compete for the starting job at Vanderbilt. The Commodores had just two quarterbacks in spring practice in redshirt sophomore Patton Robinette and redshirt freshman Johnny McCrary. But the field gets crowded this fall with redshirt junior Josh Grady and two incoming freshman.

Robinette was 46 for 88 passing for 642 yards with four TDs and five interceptions. He also added 214 rushing yards and seven scores. Grady was 3 for 6 for 27 yards and two interceptions.

Rivers spent 2011 as a redshirt and played in four games in 2012, going 0 for 2 passing. Last season, he did not play in any games.

The 6-7, 225-pound quarterback from Athens High School in Alabama, signed with LSU in 2011 as a 3-star prospect.